Using the em unit to specify the width of a website layout is one of several ways of adding a bit of flexibility to your design. If you’re not familiar with em-based – or elastic – layouts, I wrote a bit more about how they work a few years ago in Fixed or fluid width? Elastic!.
The reason I’m bringing up em-based layouts is that I want to highlight two things that are often overlooked. One is setting a maximum width for the overall layout, the other is using percentages to specify the widths of child elements like columns.
Posted in CSS.